La Soufriere 2021: Recharge, remobilisation or complete renewal of a magmatic system

形成熔岩穹顶的火山喷发构成了重大危险，因为它们往往会持续很长一段时间(通常是几周到几个月)，而且往往会从缓慢的渗出迅速转变为猛烈的爆炸。新的熔岩穹顶喷发的开始提供了一个难得的机会来进行快速研究，以了解新的熔岩来自哪里；并测试关于喷发将如何进行的想法。2020年12月27日，新的熔岩穹顶喷发在东加勒比海圣文森特岛上的La SouFriere火山的顶端火山口开始，在经历了一段短暂的异常地震活动后。新的熔岩穹顶一直在稳步增长，喷发到顶峰火山口的地面上，旁边是1979年喷发的一个旧熔岩穹顶。西印度群岛大学地震研究中心(SRC)的科学家们一直在监测这一事件，并在2021年1月16日收集了一些新的熔岩样本。圣文森特在20世纪70年代曾两次发生熔岩穹顶喷发。1971-2年，峰顶火山口形成了一个熔岩穹顶，当时它被洪水淹没了。经过3-4个月的缓慢穹顶生长后，喷发结束，没有爆发活动。科学家当时采集了一份熔岩穹顶样本，其中一块现在保存在美国史密森学会。1979年，一次新的喷发以一系列猛烈的爆炸开始，然后在接下来的5个月里转变为稳定的熔岩穹顶喷发。我们对圣文森特新喷发的熔岩的快速反应研究将回答新岩浆从哪里来的问题。我们预计有几种可能性，我们的观察将使我们能够计算出哪种可能性最有可能：-这是刚刚上升到火山中的新一批岩浆吗？如果是这样的话，我们能理解为什么吗？-这是之前一次喷发留下的一批岩浆，当时已经被干扰，并因此开始喷发吗？如果是这样的话，我们能理解这个系统是如何受到干扰的吗？在这两种情况下，我们的发现将直接提供给负责火山应对的科学团队正在进行的调查，并将有助于发展和确定关于火山喷发接下来会发生什么的想法。

Volcanic eruptions that form lava domes pose a significant hazard, as they tend to last for extended periods of time (often weeks to months) and can often switch quickly from slow effusion to violent explosion. The start of a new lava dome eruption offers a rare opportunity to carry out a rapid study to understand where the new lavas came from; and to test ideas about how the eruption will progress.On December 27, 2020, a new lava dome eruption began in the summit crater of the Eastern Caribbean volcano of La Soufriere, on the island of St Vincent, after a short period of unusual seismic activity. The new lava dome has been growing steadily, erupting on to the floor of the summit crater, next to an old lava dome that erupted in 1979. Scientists at the University of the West Indies Seismic Research Centre (SRC) have been monitoring events, and collected some new lava samples on January 16, 2021.St Vincent had two previous lava-dome eruptions in the 1970s. In 1971-2, a lava-dome formed in the summit crater, which at that time was flooded. After 3-4 months of slow dome growth the eruption ended, and there was no explosive activity. Scientists collected one lava dome sample at the time, and a piece of this is now held in the Smithsonian Institution in the USA. In 1979, a new eruption began with a series of violent explosions, and then switched to a steady lava-dome eruption for the next 5 months. Our rapid-response study of the newly-erupting lavas on St Vincent will answer the question of where the new magma has come from. There are several possibilities that we anticipate, and our observations will allow us to work out which possibility is the most likely:- Is this a new batch of magma, which has just risen up into the volcano? And if so, can we understand why?- Is this a batch of magma that was left over from an earlier eruption, which has been disturbed, and has begun to erupt as a result? And if so, can we understand how the system was disturbed?In both cases, our findings will feed directly into the continuing investigations by the scientific team in charge of the volcano response, and will help to develop and firm up ideas about what will happen next in the eruption.